/**
 * BibSonomy-Scraper - Web page scrapers returning BibTeX for BibSonomy.
 *
 * Copyright (C) 2006 - 2016 Knowledge & Data Engineering Group,
 *                               University of Kassel, Germany
 *                               http://www.kde.cs.uni-kassel.de/
 *                           Data Mining and Information Retrieval Group,
 *                               University of Würzburg, Germany
 *                               http://www.is.informatik.uni-wuerzburg.de/en/dmir/
 *                           L3S Research Center,
 *                               Leibniz University Hannover, Germany
 *                               http://www.l3s.de/
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.bibsonomy.scraper.url.kde.mendeley;
import static org.bibsonomy.util.ValidationUtils.present;

import java.net.URL;
import java.util.Collections;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.bibsonomy.common.Pair;
import org.bibsonomy.scraper.AbstractUrlScraper;
import org.bibsonomy.scraper.ScrapingContext;
import org.bibsonomy.scraper.converter.CslToBibtexConverter;
import org.bibsonomy.scraper.exceptions.InternalFailureException;
import org.bibsonomy.scraper.exceptions.ScrapingException;
import org.bibsonomy.scraper.exceptions.ScrapingFailureException;
import org.bibsonomy.util.WebUtils;

/**
 * @author Haile
 */
public class MendeleyScraper extends AbstractUrlScraper{
	private final Log log = LogFactory.getLog(MendeleyScraper.class);

	private static final String SITE_NAME = "Mendeley";
	private static final String SITE_URL = "http://mendeley.com";
	private static final String INFO = "This scraper parses a publication page from the " + href(SITE_URL, SITE_NAME);
	
	private static final List<Pair<Pattern, Pattern>> PATTERNS = Collections.singletonList(new Pair<Pattern, Pattern>(Pattern.compile(".*" + "mendeley.com"), AbstractUrlScraper.EMPTY_PATTERN));
	// input: citation_json = {"authors": ...};
	private static final Pattern BIBTEX_PATTERN = Pattern.compile("citation_json = (.+?);");
	
	private final CslToBibtexConverter cslConverter = new CslToBibtexConverter();
	
	@Override
	protected boolean scrapeInternal(final ScrapingContext scrapingContext) throws ScrapingException {
		scrapingContext.setScraper(this);
		final URL url = scrapingContext.getUrl();
		try {
			final String bibTex = WebUtils.getContentAsString(url.toString());
			final Matcher match = BIBTEX_PATTERN.matcher(bibTex);
			if (!match.find()) {
				this.log.error("can't parse publication");
				return false; 
			}
			final String strCitation = this.cslConverter.toBibtex(match.group(1));
			if (present(strCitation)) {
				scrapingContext.setBibtexResult(strCitation);
				return true;
			}
			
			throw new ScrapingFailureException("getting bibtex failed");
		} catch (final Exception e) {
			throw new InternalFailureException(e);
		}
	}
		
	@Override
	public List<Pair<Pattern, Pattern>> getUrlPatterns() {
		return PATTERNS;
	}

	@Override
	public String getSupportedSiteName() {
		return SITE_NAME;
	}

	@Override
	public String getSupportedSiteURL() {
		return SITE_URL;
	}

	@Override
	public String getInfo() {
		return INFO;
	}	
}
